A resectoscope device is employed transurethrally to perform prostate and bladder surgery. This device has an elongated outer cylinder usually made from stainless steel, which is inserted in the urethra. Inside the cylinder, a working element is employed to remove the desired tissue using diathermy coagulation. The outer elongated cylinder prevents the urethra from collapsing while the desired tissue is removed.
The current method to remove a benign or cancerous prostate or bladder tumor is called Transurethral Resection of the Prostate or Transurethral Resection of Bladder Tumor. The conventional method uses diathermy coagulation to heat a conductive wire in order to cut the desired tissue. The surgeon manually extends the cutting wire loop beyond the end of the outer sheath to a position engaging the tissue to be cut. Thereafter, the cutting element is electrically energized through the actuation of the diathermy unit. The resected piece of tissue is pushed into the bladder by the continuous flow of fluids from a reservoir through the resectoscope. The surgeon views the target area through a telescopic system. A continuous irrigation system is utilized to keep the line of sight free of blood, debris and resected tissue. During prostate surgery it is common to cut away between one half and one gram of tissue each minute. It is quite common to remove 20-100 grams of prostate during a single procedure.
A 5% glycine solution is commonly used during transurethral resection of the prostate or bladder tumor. This fluid is isoosmotic, but has the disadvantage of overloading the circulatory system causing cardiac complications. Furthermore, before the procedure is completed the bladder must be irrigated and emptied from the prostatic tissues debris, blood and fluid. It would, therefore, facilitate the procedure if the irrigation fluid is normal saline, which is more physiological. It would also facilitate the procedure if the irrigation fluids, blood clots and tissue debris could be removed without having to irrigate the bladder.
In the diathermy unit previously described, electricity is used both to cut and coagulate the tissue. The exact depth of the resection cannot be gauged in diathermy coagulation. Moreover, this type of procedure has a tendency to produce scarring and retrograde ejaculation.
The use of the laser is replacing the conventional resectoscope because it allows the use of normal saline. The laser produces less scarring, and reduces the risk of retrograde ejaculation.
U.S. Pat. No. 5,312,399 issued to Hakky and incorporated herein, shows a modern laser resectoscope with electrically induced mechanical cutting means and laser coagulating means.
There are two types of laser delivering systems: non-contact and contact.
In the non-contact laser, a fiber optic with a 400-600 micron diameter is used to deliver the laser at a distance of a few centimeters from the desired area. The laser coagulates or carbonizes the tissue depending on the amount of wattage used and the duration of laser delivery. The tissue coagulates at 55-90.degree. Celsius and start to vaporize or carbonize at temperatures exceeding 100.degree. degrees Celsius. U.S. Pat. Nos. 4,955,882 and 5,312,399 (Hakky) disclose a resectoscope device embodying a laser for use in coagulation and removal of the prostate and bladder tissue. A cutting blade is provided in that device for cutting away tissue which had been coagulated by the laser. The tissue is either side or end lased, e.g., the laser is directed at a right angle to the laser delivery fiber, or at the tip of the laser delivery fiber respectively. Another laser device on the market is offered by Intra-Sonix, Inc. of Burlington, Massachusetts for affecting what it refers to as "transurethral ultrasound guided laser induced prostatectomy" (TULIP). This device utilizes a laser mounted on an ultrasound transducer introduced transurethrally to heat the prostate tissue to the point that it becomes necrotic, that is, the living prostate tissue becomes pathologically dead. The necrotic tissue sloughs off and is expelled in the patient's urine over an extended period of weeks or months following the procedure.
In the contact laser, a probe made of sapphire or quartz is employed to deliver the laser energy by direct contact of the laser probe with the desired tissue. Certain disadvantages are encountered in the current contact laser ablation. These disadvantages include adherence of the tissues to the tip of the probe, prolonged procedure times, high temperatures needed for tissue vaporization, and the destruction of tissue that is needed for histological diagnosis. Surgical Laser Technologies of Oaks, Pennsylvania offers a "contact laser". The probes in this laser can only be utilized for benign prostate tissues. Moreover, no tissue can be removed for histological examination. As explained above, the patient is expected to expel the necrotic tissue left behind in a matter of weeks or months.
There are some principal disadvantages in the prior art. In both the non-contact and contact laser delivery systems described above, tissue is not removed for histological evaluation. Furthermore, once necrosis sets in, the tissue is left to slough spontaneously. This can cause infection, scarring and urinary retention.